SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67823606fda56bf2f819adc538831da20d16ca13f36312453dbaf312512d362c' 
  AND token = 'Km4d8I471tUQmhb6t+1bC8Am4JIW6T6AW4HqPgI4qb4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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