SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18da5ecab342ef95595fd8d49c5b6eb6b4b156a2109bb5c48b9a57f79578b10e' 
  AND token = 'HyUx5WrtmEyOHe4zFSBxR4z2sUGI5pdkp5dITafuaXQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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