SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '363f192c05426eae399ad860fbbb935332c1f2c7ea8f2d7feade8df2a4a781f1' 
  AND token = 'nu4R3Gs5KUcMPidVlOYC/yVYJJxZF2sMnXEq6TdHxeg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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