SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '716742adccda4c7bbec44b670f022215916d108051a6d1d361752bef0c24e9d4' 
  AND token = 'RFNfA1vigHjblM/mksSDuQwldNiTVp0It6rZdi+pcM8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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