SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1eeee06096ab7469b3dc99a46870abe22dcd94ccbcee667b95660c3f9c0534c' 
  AND token = '6erwC/O42UiR54mEV6q2XNsBZmb5cPIlhkAyoIdqLiQ=' 
  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"
    }
  }
}