SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f452d5d79ae06da6f82bd918204bdcb87a070edb17cf4520f60282fced41ce0' 
  AND token = 'xOL5BQBWsDY7Etf55Xii11ltCNSJAcubMAipjXgFNRU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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