SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7e76b103afa19a73c01f3cd207c18478485c64e2cd66556154995fea26a07cc9' 
  AND token = 'mm1RBMlvzyXdnSjLn6EnMQ1rRdEvBehV9A0eMZZG/RE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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