SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7443aa17121919a84203a5c390b61ea470f2b26ae075d13fabb46f75daad4a33' 
  AND token = 'JqbHoFPutBXks+owWo6KC37/WGjW0LnZEHtmfhUp3ps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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