SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61667764af9bd4e7fa7dffcd9d5d6989e2919092071114d64bf283f984488c1a' 
  AND token = '/PsHiYdPn3rA6E9R27i7ITuhK3fpFld47S8y5AgrnJY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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