SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2592819d4eda9281114ccaa3c6e75b596ec4826fa242aa325fc2b9ebe2d7f25' 
  AND token = 'NIG4sNV93dsmgcrtcPBoDc4PysJ5XNKkzbW9XAD+Ll4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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