SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea21c1dc77dcca5c843647b93a57b94bbebee169420846694a3a02febf4363bb' 
  AND token = 'TO241ZR5jZ33B78s2+oI6aAckX0HKWUk42eAf7BqO+k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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