SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'de87f6a13995d9b2963c25f30fb941141534a8a78a3593a97c9dc686eb6678d9' 
  AND token = 'DCNrO6/+EYotMpFkOKw9+R2IoZgwdSLSTrcU7C5ofy0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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