SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59bbf10104123c90c2af374a17edfd20b49e6e3111c44edce92f9fbb176652bc' 
  AND token = 'MJhMQYElVzwXDPhdJLcYeHbxoZ5w7jKu5XL9TveKXbY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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