SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd27e7fb8b02438eea0213e7d1597fedb6f8be25d9eb815800866cfc7743cb32c' 
  AND token = 'fUDK91dX0H3pgl9hivGAjuEswhRqpQ3MCyo9jyEvz+k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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