SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0edf98c6a449f6f1b261d6db08df1d2b5e8620c74f9fed6de149958042e9bf2c' 
  AND token = 'IjrHw32z/0OlWEwwBvkeROJD9OTtJayP9YiW99y5FBE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}