SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78991a25fd9fec58243ea7da4c1ba023c435657b6704c18acf0d05457df56c23' 
  AND token = 'V5eVk+1z67IQFEG5lJ0Y6JKpjePU9Owl8sfaOMQRqVw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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