SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a14cb97730090a033950cab3ecf6298fe90cc0fd214c463cfb100d47cf99e9b' 
  AND token = 'eECemYBsTNacVl0XPNsbRpP6a41PVcuaPw1Q+c2Ayo8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}