SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db73a35f00b09d88c1b12d7a52847e267470f2550119a71f9812a7937bf97763' 
  AND token = 'UbM9ChRrmrrJb5jnFG8SknF7e7qsYYRnIrlwCpVQOso=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00132

JSON explain

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