SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '226288baca99406e27b52532dc834e3d04964ad0c5b0b69fc4ca3ee98b30b2f0' 
  AND token = '3CVy47IGbplC5zRkmma1MuabrfwmqdYs9VIg5CIsLSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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