SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd42ea4de9b71b5da42fa685256d25015f3a9c46c684980922f47031612ba513c' 
  AND token = 'DoLk0lRsVvPxvgwV1k7AODh/AR3ig4q67PIAHNG7u24=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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