SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89ae2a62dd9f5e5d0ec2f7255e5ed3a01098ab9591b12e9df7b2b5d7645d0d85' 
  AND token = 'JxOVsJW72c2XbXWtfITvuyrzMOeMo31WxjbCpA9/1yg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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