SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89e224429796c283dff6e56a787d8705d1d2f7abb9592f3103234968c118b5ed' 
  AND token = 'Et21pQzn6O/ys9DfWTA4le90538/Wb1yzHCBLylTkCg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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