SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd0ac8998ba141502450bdccce264a1dc1948ae26083c81f0262a093043557841' 
  AND token = 'AYLca/8sINMJLrnDaPFK+DliaYlHDmUxgeZOnVC3DDE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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