SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '287ff06f9aef13d4fbc69acf87bfd2d428e610537c21b548666709383f1d555b' 
  AND token = 'nuDKAcD4opxPydxmIjZZpkoA2kABemr31F3hEADFJuQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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