SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80b00e5c4e7551845dfedbb7ac46094dffc92040046f40f280c3b142852e15fb' 
  AND token = 'ssd87BywI11jFTeQKnoYGKouSezuihkDof2OLqZy3pc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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