SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6414b13be921866a6d1553f3679b34ba949e9edff24c2787c56a5946cf9b141e' 
  AND token = 'Nh6So7m3zl/GqjNXDQm16GPGO5V+WggdeqgWawEvNIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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