SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb7ff06c0c16cf69760d9fb0ef180fb2a78cb0e899c299f2bee1973d55c275f6' 
  AND token = 'y2xUJRyJ+je8klCxkoCSMjl2O/uqNjSHaJpiQIbQfBA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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