SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2cec2b31913748f7a150b7845b7e201d22e0aeaaed3780366ede0c3bf1f0d86' 
  AND token = 'UC+xok2KPrOuKAKusIhHe9ovtTu01OXc2YLaNXFhWk4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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