SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9775b1ab5bce9cad51a6ba8307ef53aebde4ae2de220f0f993cfca9adb73d796' 
  AND token = 'IbYM5+zwFlIIdW69uBA17Sb4PEeEe/ULMthOKyqbX4o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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