SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab7a4ed9b37fd78291708bb7192f73255307129281c4253b26ee0b04e2c78b67' 
  AND token = 'Vix9lE8gdti0tJdJAUYdRwzBfpCFEL3RohOa/5elw9E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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