SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0d2992f52f6f957b9d6dfc52bc0df82cd610d49ba84dc8dff279689267deb4f' 
  AND token = 'YdN/uO0BzIRMZMpfFraGSImsY5IyjWLuZs/0dDPdPqQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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