SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b33d99195fdb90f1ad600baabfd65acdcf66c704dac07d06eda1938565e90c65' 
  AND token = 'RD83Hw6muaxXLgerCPwOivCZ0iSEBxJrQoYyjUt9gjU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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