SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '155ecddcc09b7dca0543c8a5ff1474c10eabd81f32ee697287742d5dcffeef60' 
  AND token = 'eQkb2zhEiwqwjKqY0zMEFGRiQE8eLcVPZwRkOVzwcmM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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