SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b8102e5776f9292fd9c100abe4e69a1c870ef0be0362bf8371a0c18bd4be40b' 
  AND token = 'lU196VbfzTSKOLwEpJoffTQZeK3TRgGss2U6sQe4D3M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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