SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8bdbbacd26e651dc543bf16fc808dc29fa065b95b1846271f443ca1ddbe271e' 
  AND token = 'FK+a6w8fBHfZ3Oog8dVl1/NgDOuTpK4VecpLC/T2wuU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}