SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5f192285acd664a2c30d42574ca31b7d388db1a4a4270c8f74589db8e71a33a' 
  AND token = 'wI0pV3THvOiLT0rsC+Oo2pYP9P3zlprsqn453n422uk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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