SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1aebef47c589df482e43b54c38fbff8e49651906e10be954189c99324ea9e71' 
  AND token = 'JUBrioXIqVTNiMO0V3914nVn38clIbQFWKvTPHrk4ks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00079

JSON explain

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