SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d15ad060497dea926eebdb4b10d27cf077823ac3c4dd0f336a0315e543fcdf8' 
  AND token = 'gTSfVRLOh6wVUa+7mebUTi6lKoGtEItFnotDW6caQIo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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