SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '370556011d01e85776c084bb88e2cd57f66c12a757992a15254d452a747b4721' 
  AND token = 'jpppaJ3LVfyaDMoF8/e3Zj1xgns8kZZPdB8p3ukjjIA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00059

JSON explain

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