SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec696a771281a8be2e167afffeff375fe6053115367a33345f7bdc8ec94b9276' 
  AND token = '/YlOGjLOGnWjDGUBwISzo/CTsB0OiqJMHsip251G3M4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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