SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3f193ec4434f1e698fcc54a9fac3d48f1c880e2694d0cfcc0cb671622e056f0b' 
  AND token = 'ETyyMur4qBGz0saf9mo/o1SbVc/JQ+xfODiokhoFMyI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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