SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6656d0b9a6025605cc176f1ca9cdb6e4af328bcb834a7a52ede372b82552140' 
  AND token = '5cVXqA8t7V/PSe9WH0g2xTlbBwwxiP1GXcYFUgv8hjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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