SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '790bfef93736de76d62a48f680a4b3d01e1598a4215c6c07089419aefcff95d1' 
  AND token = 'lv3I465sfiu0e2KrLwG6q7fHaKj5jEiYTeZDFXBgLUQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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