SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b5b09c0f0e24b10efefd2aecbe53ce0420c1840b110b8939942c44ca7ba0291' 
  AND token = 'FRqZ5WgOcKxiCbzYnyy06GnULDNuuOSuo/nl+qymvNg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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