SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53c040aa875fbddd03deaa23b862f4b746eacd6c16ffa8ca2c181874edada200' 
  AND token = 'ZM+YUVzv7ZxWXC9yeqez+9PDM9HezTV0XvxeLieX4KE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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