SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a6465759a7ac049753f31d51fc146e1c710dbcb288b580ce2bffbdedfae2bd3' 
  AND token = 'rgP/AXWYeXVsIlaoBgpEXLDncJeuSI0ZKl7RqJlYiS0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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