SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c93cb219b9c7810b15e10812f40433da9bc388daf057fc3dcb01ad5fe7670d0' 
  AND token = 'p0TBoV45DOEnB5qEcAwLcYkerFA6gqavsWkdcVnpink=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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