SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97cac28db8da8bf0514389d2ea7bdd6e0a29cff498b96211043eef86ebf2e4e2' 
  AND token = 'RP2x339nNXlF9/RWYbzHeqbRHMtaqbu4fCBGE3MnTJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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