SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b219c47c3109875ba998727407f5d22a57d9e8f4bbc7b5a92a44a661104f54e' 
  AND token = 'RLTzaS4HwgVaKZCoZcz/8p2X501jdOQRwnGlUrFA7tU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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