SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18327ca7df830c4f0efbbe8bc81d318d71079052af073a68a2797f64fc28d566' 
  AND token = 'XN8GGCswaRQg6WxaSXbmQJLiVMH4g7d98XvKPtoyTPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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