SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '614525c69861f8a283f0e8655c48504f48eb39015c448cf52f7bf90b49b911e3' 
  AND token = 'dEbEEEgx5Km/7kTXFKzHOb7txV4hZNQmwee8R6ooYms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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