SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69261a1786121365bb0658faf5d84c52e2f82fe2b91ad487677afba886e58429' 
  AND token = 'kpClzpDnY7tj6bH7CM15bN0KW6PjR6qZd9J5ihrd52Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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