SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b360f2b9c4a61a6d3361b0cc16cb68a6326c329aaccc47b13bc8317b1be6709c' 
  AND token = 'pwdDD+TtuZzorGhkURI7yoejURdiV0NPcjk/NxH2+lQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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