SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '635edcdd3b77f9d922816dde51150e0b1f13fb8355c030f70cd5f7797560a3a7' 
  AND token = 'mYrOgtJslVJg0mIoscLpn97D35Qg2DKnPXMZ58SKkLg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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