SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4a61a36ace1c14c884228053867273c3f0f5d2166c08cb0fae4a18346e4725eb' 
  AND token = 'L/3xbesYza4Qu01tOEOtb/AEtEphnY3RHdAgnGSpFpM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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