SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8dc7604c8b2159ab545b0f9a56144a5a0138f9bcd4c28ef0ed6a38514223cb53' 
  AND token = 'uiyGsC9lFwUWeMpzSRoJspHDKsxORh76JXmn54S1a/s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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