SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd63788954bc6c0b94a33dc259e199fcd131c3d88821991fbf968b66a7bdcc109' 
  AND token = '25c7JN9NHzRyBWtAFzWc68SllyO21f26EhdV0H5KOvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}