SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f759b49148f124531b8f665e790f84939b44c579336c48d7f2efcf1296e40f18' 
  AND token = 'qHSXTn4Qh6BEs/PC1FlvZNvQSyLZP74K4LFvPmaJ1hs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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