SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8573cb22941397ccf287e10e1e96ead0d67c306779dae66a40ca06400033c4c7' 
  AND token = 'lmzDAxmcjf/9UVTpplZMxxYs6DfHbUS9/pB5g7GivoU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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