SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0397c0ef5e86eab0afe01635f1525cd367e3b524ca386e14aa1efa680cc873f7' 
  AND token = 'YclINauOSffuJuFBK3Aq4PpYz4sj1K/fpMmzrCqdgVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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