SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d1d2e6a036cab70c65461a1c4cab86818e631e08d5476de33b9a311b11314bd' 
  AND token = 'eBs9iQ3QSfTP6qhuW8V9lsz/RqTQ2p9RBq+6O95/P4I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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