SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ec485258fcc40ecb1b5405a5d74e0253954931a0cf59fad5cf750a79d9a706b' 
  AND token = 'MLCaz/d32ENt5K7DssYZYXHIe8l2JaeTQZ4DTAjog2k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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