SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9adc27d7b41ee0aea02bc5eed4e6cb4aedd206b481163952c5711c13ca9461f7' 
  AND token = 'FiQjsIkDcMgKkIjmMA4x3eZup9kpwXHi8BoK72JVtx0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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