SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1671bbcc88df0bd904030b7c2886307b7bc7bc80eab103647db906a719534d6' 
  AND token = 'BFL0vWs6e2WagWAfJcfS/S7f9+2+qhmvcZgk+13sEN0=' 
  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"
    }
  }
}